1. Field of the Invention
This invention relates to an image generation method and an image generation apparatus for generating dot patterns from edge-address information of an image.
2. Description of the Related Art
A method has been known in which, when transmitting binary image data, so-called dot patterns (bit maps), in which one bit of data corresponds to one pixel (dot), are used, run lengths, each comprising continuous white or black dots, are used, and data is transmitted in the form of edge addresses, each indicating a point of change from a white dot to a black dot or from a black dot to a white dot.
The edge address is an address of a dot constituting one raster (a scanning line comprising dots), and is expressed by the number of dots from the leading dot of the raster in the simplest form.
When edge addresses have been input, processing of converting the edge addresses into a dot pattern for inputting data in a recording head is required in output processing of a printer or the like. Conventionally, when obtaining a dot pattern from edge addresses, a start edge and an end edge constituting a partial image are used as dot information of the partial image, and a portion between the two dots is painted.
That is, processing of obtaining dots corresponding to the start edge and the end edge in an image memory, and providing white or black dots in a portion between the two dots is performed.
In another approach, a dot pattern is generated by converting all constituent edges into dot positions to provide the contour of a pattern in a two-dimensional image memory, and painting the region within the contour.
In the above-described conventional approaches, however, two processes, i.e., a process of obtaining dots corrsponding to a start edge and an end edge, or contour points, and a process of painting a portion between the obtained dots or a portion within the obtained contour, are present. Hence, complicated processing, such as calculation of addresses, processing required when a plurality of contours are present within the same word, or the like, is necessary, thereby increasing the cost of calculation.